The present invention relates to a filler, in particular, to a filler provided with a sampling mechanism.
A filler is usually designed to open a liquid valve in a filled liquid passage formed within a filling valve to allow a liquid fed from a filled liquid tank to be filled into a vessel and to terminate a filling operation by closing the liquid valve upon detecting by metering means that a given quantity of filled liquid has been filled. In such a filler, a weight which is filled into the vessel is determined by a sampling test in order to confirm the accuracy of a filling operation for each filling valve. A filler which is provided with such a sampling mechanism is already known in the art (see, for example, Japanese Laid-Open Patent Publication No. 2002-362502).
A sampler disclosed in this citation is installed in a filler in which conveying means convey vessels one after another to a filling position where a filling mechanism comprising a plurality of filling nozzles fills the vessels, and includes a tare measuring means and an actual vessel measuring means disposed upstream and downstream of the filling mechanism for measuring the weight of the vessel before and after it is filled. The tare measuring means and the actual vessel measuring means are each constructed such that a vessel is extracted by a gripper as it is being conveyed by the conveying means, handed over to a weight meter which measure the weight thereof, and then returned to the conveying means.
In the arrangement of the sampler disclosed in the citation, there is a need for an apparatus which extracts a vessel from the production line on which vessels are conveyed and filled and returns it to the line after measuring the weight, with consequent problems that the apparatus becomes complex and bulky, requiring a large space for its provision and resulting in an increased cost. Another problem arises also that the sampling operation must extract and return a vessel from and to the line and thus takes a time. In particular, in an arrangement where a plurality of vessel are conveyed intermittently and are filled concurrently, the sampling operation must be repeated a number of times equal to the number of the nozzles, resulting in a prolonged length of time required for the sampling operations.